import React, { Component } from 'react';
class ChildB extends Component {
  constructor(props) {
    super(props);
    this. state = {  }
    // console.log(props.children)
  }
 
  render() { 
    return ( <div>
      childB：通过props.children获取插槽内容
      {this.props.children}
      </div> );
  }
}
 
export default ChildB;